A volcano in south-western Japan has erupted for the first time in six years, spreading ash over nearby cities and towns.

Japanese broadcaster TBS showed elementary school students wearing helmets and masks on the way to their school at the foot of the Shinmoedake volcano.

Residents also described hearing rumbles from the volcano, and ash fell in at least four cities and towns in Miyazaki prefecture.

The volcano on the border of Kagoshima and Miyazaki prefectures started erupting on Wednesday for the first time in six years.

On Thursday, an ash plume rose 1,700m from the crater, the Japan Meteorological Agency said.

The agency has raised the volcanic alert level from 2 to 3 on a scale of 5. Level 3 warns people not to approach the volcano.

It forecast that the crater would continue to emit ash and potentially volcanic rocks until Friday, but the locations at risk would depend on wind conditions and altitude.